1. Field of the Invention
The present invention relates to a method for producing a semiconductor crystal based on the growth of a Group III nitride-based compound semiconductor crystal through the flux method.
2. Background Art
Hitherto, the flux method has been employed for producing Group III nitride-based compound semiconductor crystals. Japanese Patent Application Laid-Open (kokai) No. 2005-194146 and other documents disclose such production methods. In those conventional production methods, a plate-form seed crystal is horizontally positioned at the bottom of a crucible, and a semiconductor layer is grown atop the seed crystal. Generally, only one seed crystal plate is placed in a crucible.
Japanese Patent Application Laid-Open (kokai) No. 2005-187317 discloses a similar crystal growth method in which a plurality of plate-form seed crystals are vertically held in a growth apparatus. Each seed crystal plate has a surface of growth (hereinafter referred to as growth surface) which assumes the (001) plane. This publication does not disclose in detail the manner of holding a plurality of seed crystal plates.
According to the aforementioned conventional methods, effective utilization of the interior of the employed crucibles is not satisfactorily attained. Thus, conventional production methods encounter difficulty in ensuring sufficiently high production efficiency. Also, when a seed crystal plate is horizontally placed at the bottom of a crucible, a raw material solution is not supplied uniformly to the growth surface of the seed crystal plate, making it difficult to produce a semiconductor crystal of interest with highly uniform quality.